1. on Elm street there are 6 houses on one side of the street
and 4 houses on the other. Each pair of houses on the street is connected by exactly one telephone line.
the total number of
such lines that connect
houses on opposite sides 12
of Elms Street
2. 9510 SEC1的第12題 有一個長方形圖表的那題
為什麼r+u+v 會等於 r+u+v+w阿 ?
3. 9510 SEC1 第9題, 為何答案是A?
很抱歉有兩題我沒辦法畫圖出來@@
希望有好心人幫忙一下囉!